late period but negative tests

I am so frustrated, i'm now in cycle day 39 when my average is 35 (the last few months it's 32) so i'm usually longer cycles. i've taken test after test for the last week and all negative. I had a weird one picture attached that didn't look quite right last friday. Maybe I was pregnant for like a day and it just went away but wouldn't I have gotten my period by now? maybe i've just not ovulated this month, put too much pressure on myself. This is only 3Rd month trying but i'm so incredibly confused and frustrated. please offer advice/comfort :(